Semiconductor Memory Device Refresh Scheduling During Fuse Programming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor memory devices face data retention issues during post-package repair operations due to the disregard of refresh operations during fuse array programming, leading to potential data loss as peak currents are increased, affecting the reliability of memory cell data retention.
Innovation Solution
A semiconductor memory device with a control unit that sets up separate and non-overlapping program and refresh operation sections, ensuring a refresh operation is performed before or between program operation sections, thereby maintaining data reliability and preventing peak current issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If refresh operations are performed during fuse array programming, then data retention in memory cells is maintained, but peak current increases affecting both program and refresh operations
Solution Approach 1:
The operation timeline is segmented into distinct program operation sections and refresh operation sections that do not overlap. The control unit identifies the duration of the program operation and schedules refresh operations to occur only during periods when the program operation is not active, thereby separating the two operations in time to avoid current叠加
Solution Approach 2:
The control unit preliminarily determines the duration of the program operation section and proactively schedules refresh operations to occur before or between program operation sections. This preliminary planning ensures that refresh operations are performed at appropriate times without causing peak current issues
2Stability of the object's composition
If refresh operations are ignored during program mode, then program operation stability is maintained, but data in memory cells may be lost due to extended retention requirements
Solution Approach 1:
The system dynamically adjusts refresh operation scheduling based on the program operation status. Rather than statically ignoring all refresh operations during program mode, the control unit dynamically determines when refresh operations can be safely performed by monitoring program operation progress and duration, allowing flexible optimization of both stability and data retention
3Productivity
If program and refresh operations overlap, then operational efficiency is improved, but current interference occurs affecting both operations
Solution Approach 1:
The control unit implements periodic refresh operations that are synchronized with the program operation schedule. Refresh operations are performed in periodic intervals during designated refresh sections that are determined based on the program operation duration, ensuring regular memory maintenance without interfering with program operations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures stable data retention by allowing refresh operations to occur independently of program operations, reducing the risk of data loss and enhancing overall data reliability during post-package repair processes.
Implementation Method 1
The anti-fuses are provided because such operations cannot be performed in the package stage. Anti-fuses generally begin in an open state and may be short-circuited by applying a high voltage to break down the dielectric material within.
Data Source
AI summary
A semiconductor memory device includes a memory cell array including a plurality of memory cells and a plurality of redundancy memory cells, a fuse array to be programmed with information of a defective memory cell among the memory cells of the memory cell array, and a control unit suitable for setting up a program operation section for programming the fuse array in response to an external command, wherein when the control unit sets up the program operation section, the control unit sets up a refresh operation section for refreshing the memory cell array, which is terminated before the program operation section ends without overlapping with the program operation section.